Abstract: The present invention relates to a system for measuring a grinding force between a workpiece and a grinding wheel during the operation of a computer controlled grinding machine. A force transducer is mounted on a drive screw assembly between a moveable slide and a motor used to control movement of the slide. The force transducer generates a control signal that is conditioned and received by a digital signal processor, which instructs a machine controller to perform grinding operations in response to the measured force.

Abstract: A centerless grinding machine comprises a stationary disk, a following disk, and a shoe, which cooperate to hold and rotate a workpiece. The following disk is mechanically loaded to the bias towards the stationary disk and the shoe so that the workpiece is secured between an outer circumference of the disks and the shoe. A diameter detector detects an outside diameter of the workpiece by detecting a displacement of the following disk by the workpiece. From this information, a controller controls an X-Z grinder to grind an inner surface of the workpiece. This grinding is in response to the outside detector detected by the diameter detector. As a result, the inner diameter can be machines to closer tolerances than are available in the outer diameter.

Abstract: A workpart chuck centering mechanism moves towards the axis of rotation of the chuck as the chuck rotates in an eccentric non-centered position. The centering mechanism includes two independent shoes. Each shoe is driven by a servo-motor and encoder. The two shoes function in a cooperative manner to center the workpart. A sensing device monitors any eccentric movement of the workpart and controls the positioning of the shoes. The two shoes and the sensing device are mounted on a base which can pivot about the chuck axis. The directions of movement of the respective shoes are displaced 90.degree. relative to one another and intersect at the chuck axis.

Abstract: The present invention relates to systems and methods of controlling the dressing operation of computer numerically controlled grinding machines. A contact probe is positioned relative to a dresser and contact measurements are made to determine the position of the dresser tip relative to a pivot axis about which the dresser rotates.

Abstract: A workpart chuck centering mechanism moves towards the axis of rotation of the chuck as the chuck rotates in an eccentric non-centered position. The centering mechanism includes two independent shoes. Each shoe is driven by a servo-motor and encoder. The two shoes function in a cooperative manner to center the workpart. A sensing device monitors any eccentric movement of the workpart and controls the positioning of the shoes. The two shoes and the sensing device are mounted on a base which can pivot about the chuck axis. The directions of movement of the respective shoes are displaced 90.degree. relative to one another and intersect at the chuck axis.

Abstract: A dresser is moved on a pivotal dresser holder arm relative to the pivot axis of the arm by a computer control unit using closed loop servo feedback from a position transducer to successively dress different radii and/or shapes (convex or concave) onto the same or different grinding wheels.

Abstract: An automatic workpart centering mechanism for a magnetic or other chuck of a machine tool is provided. A computer microprocessor controls a digital air pressure regulator and/or an air solenoid valve to supply air pressure to a pneumatic centering hammer to control striking force on a workpart as it is rotated by the chuck and held thereon by a given chuck holding force with the location of the striking force on the workpart also under control of the microprocessor.

Abstract: The workhead includes a spindle disposed on a base member and rotatable about a rotational axis. The spindle includes a chuck for fixedly clamping one end of an elongated workpart, such as a valve lifter body, having a bore between opposite ends with the longitudinal axis of the bore substantially coaxial with the rotational axis. A fluid bearing such as a hydrostatic bearing is disposed on the base member adjacent the other end of the workpart for providing pressurized fluid at sufficient locations around the other end to resist machining forces tending to deflect the other end off axis relative to the fixedly clamped end during machining of the bore to improve bore roundness and straightness.

Abstract: The workstock may comprise a tailstock having a slide which releasably carries a workpart center and which includes a center ejector member independently movable in the slide. The slide is mounted in a housing for axial motion toward and away from a headstock center to load and unload a workpart therebetween. The axial position of the slide as well as the center ejector member is monitored by position sensors to provide status of the tailstock center and workpart. The workpart center is loosened by the ejector member in the slide when the ejector member is positioned from a retracted position relative to the pocket to a center eject position toward the pocket so that a robot may remove the center and substitute another center to hold a different workpart.

Abstract: A dresser carried on a pivotal dresser holder arm is adjustable in position relative to the pivot axis of the arm by a computer control unit using closed loop servo feedback from a position transducer to successively dress different radii and/or shapes (convex or concave) onto the same or different grinding wheels.

Abstract: A workpart chuck is provided with a centering member that is movable toward the axis of rotation of the chuck as the chuck rotates the workpart in an eccentric non-centered position. As the centering member moves the workpart, a sensing device senses the extent of changing eccentric movement of the workpart and generates an electrical signal that is indicative of the extent of such eccentric movement. The workpart is moved toward the chuck axis until the signal reaches a predetermined value indicative that the workpart is rotating about its axis; i.e., the workpart axis and chuck axis are substantially coaxial. The centering member is offset slightly relative to the chuck axis of rotation to assure that excessive movement of the centering member placing the workpart center beyond the chuck axis of rotation will not result in the workpart being driven to an extremely eccentric position and possibly even off the face of the chuck.

Abstract: The method involves moving a reference or dummy tool of known size on a toolhead slide from a known position to actuate a limit switch, moving a working tool of unknown size on the same toolhead slide from the same known position to again actuate the limit switch and comparing the toolhead slide position for actuating the limit switch for the working tool with the stored toolhead slide position for the reference tool to determine size of the former.

Abstract: A loader (10) for a grinding machine includes a loading member (30) with at least one resilient finger (32) thereon for gripping a workpiece (14) to be ground by movement of the loading member in a loading direction as a resiliently biased workpiece positioner (34) initially counteracts force applied to the workpiece by finger deflection. Continued movement of the loading member (30) after the gripping first moves the workpiece positioner to a nonblocking position and thereafter moves the workpiece to an associated grinding machine. Preferably, a pair of the fingers (32) and a rigid locator (44) cooperate to position and grip a joint race (14) of an annular shape with ball grooves to be ground. A pair of spring biased blocking members (34) preferably embody the workpiece positioner and are pivotally mounted in alignment with a hopper (16) in which workpieces to be ground are stocked.

Abstract: A grinding machine (10) includes apparatus for grinding grooves in inner races (16) of constant velocity universal joints with a high production output achieved by indexing of a race without stopping rotation of a holder (14) on which the race is clamped for rotation during the grinding. An indexer (46) of the apparatus is supported for rotation with the holder (14) and provides the indexing of the race about a central axis C thereof as the holder rotation proceeds. A locater (48) also rotates with the holder (14) and accurately locates the race after indexing to provide alignment thereof with the grinding wheel (12) that performs the grinding. A jaw operator (44) controls first and second jaws (40,42) of the holder clamp and has a high clamp mode for fixing the race during the grinding and a low clamp mode for permitting the indexing and locating operations as well as an unclamp mode that permits a ground race to be unloaded and another race to be loaded onto the holder in preparation for the next cycle.

Abstract: An antifriction bearing support (12) disclosed includes an outer support member (50) for mounting thereof on a spindle housing (16) and an inner support member (52) for mounting an antifriction bearing (42) which rotatably supports a spindle (38). The support also includes at least one flexible diaphragm (54) extending between the inner and outer support members to radially fix the inner support member and the antifriction bearing and preload the antifriction bearing axially with respect to the axis of spindle rotation so as to permit high speed spindle rotation. Preferably, a pair of the diaphragms (54) are utilized and are mounted in a spaced and parallel relationship to each other. Inner and outer round edges of the diaphragms are secured between axial surfaces (80, 82, 88, 90) of the support members and associated retaining ring (76, 78, 84, 86) that have soldered connections to the support members.

Abstract: A work holder adapted to minimize clamp distortion of a workpiece by providing a movable metallic collet encompassing the workpiece, and a plurality of front and rear jaws to grip the metallic collet with different pressure forces at the front and rear sections of the collet.

Abstract: A grinding machine having a fixed wheelhead and a biaxially movable workslide. The workslide is mounted on a cylindrical slidebar for axial sliding motion as well as pivotal motion around the bar. A dresser assembly is also mounted pivotally on the slidebar for selective dressing operations. The workslide may be moved axially into an overlapping relationship with the dresser such that the workslide is carried with the dresser over a range of pivotal displacement thereof. An hydraulic cylinder is used to pivot the dresser and a precisely positionable stop is used to control all lateral feed motions. Axial speed is programmed by a control valve. The dresser is pivotal on its base to produce a true circle wheel profile.

Abstract: A multi-function grinding wheel truing mechanism that is capable of automatically imparting to the periphery of a grinding wheel either a combination radial and straight form, a radial form, a straight form, or a Gothic Arch form. A dresser unit housing swingably supports a turn post carrier which is normally biased to a first position by a spring. A turn post carrying a main diamond for dressing the periphery of a grinding wheel is rotatably supported on the turn post carrier. A single drive means is carried on the turn post carrier for moving the main diamond through a dressing path, and to accomplish all functions, including the automatic retraction of the main diamond at the end of the truing path and the automatic extension of the main diamond at the end of the return path. A cam means is operatively mounted on the turn post carrier for providing a combined rotary and swinging motion for moving the main diamond in a straight line dressing path, and for carrying out the dressing of a Gothic Arch form.

Abstract: A grinding machine having a fixed wheelhead and a biaxially movable workslide. The workslide is mounted on a cylindrical slidebar for axial sliding motion as well as pivotal motion around the bar. A dresser assembly is also mounted pivotally on the slidebar for selective dressing operations. The workslide may be moved axially into an overlapping relationship with the dresser such that the workslide is carried with the dresser over a range of pivotal displacement thereof. An hydraulic cylinder is used to pivot the dresser and a precisely positionable stop is used to control all lateral feed motions. Axial speed is programmed by a control valve. The dresser is pivotal on its base to produce a true circle wheel profile.

Abstract: A single-slide, mechanically and electrically programmed grinding machine comprising a rigid enclosed base, a fixed workhead assembly on the base, a pair of parallel slidebars mounted on the base, and a wheelslide assembly mounted on the base for longitudinal displacement thereover. Longitudinal wheelslide displacement is mechanically controlled by a motor-driven cam bearing against a spring-biased lever pivoted to the base and connected to the wheelslide via a rod. Lateral feed is independently electrically controlled by a motor-driven nut and screw shaft assembly which angularly displaces the wheelslide assembly relative to one of the slidebars and about the centerline of the other slidebar. An eccentric and variable-position spacer is provided for reciprocating the wheelslide during a grind operation. A thermally-stable base configuration is disclosed. Part load and unload apparatus, all mechanically programmed, are also disclosed.